


Shulk Gets Wrecked - Byleth

by BunnyFairy



Series: Shulk Gets Wrecked [10]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses, Super Smash Brothers, Xenoblade Chronicles
Genre: BDSM, Boots - Freeform, Dominance, Explicit Consent, Explicit Sexual Content, Fluff and Smut, Happy Sex, Leather, Like just a LITTLE bit, M/M, Masochism, PWP, Restraints, Sadism, Sexual Content, Shameless Smut, Smut, Spanking, Teacher/Student Roleplay, Yaoi, there is some consensual violence in this!!!!! like hitting hard enough to leave red marks
Language: English
Status: Completed
Published: 2020-01-31
Updated: 2020-01-31
Packaged: 2021-02-27 10:47:54
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,328
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22496716
Author URL: https://archiveofourown.org/users/BunnyFairy/pseuds/BunnyFairy
Summary: There's another newcomer in the Smash roster, and he wears black leather and has a chain whip sword and Shulk is very intrigued.  Byleth is invited to awaken his inner sadist, and reveals he has other expressions besides his RBF after all.
Relationships: Byleth/Shulk, My Unit | Byleth/Shulk
Series: Shulk Gets Wrecked [10]
Series URL: https://archiveofourown.org/series/232983
Comments: 10
Kudos: 29





	Shulk Gets Wrecked - Byleth

**Author's Note:**

> Welcome back, after a 4 or 5 year break!!!!! Byleth's whip-sword and teacher pointer thing that he holds when he appears in matches are the reasons I had to write this. Previous knowledge of this series isn't really necessary; basically it's just established that Shulk is a dirty boi, and Marth is the host of various sexy encounters between members he recruits from the SSB cast (made up of all of the cute anime guys in the game). That's it that's all the backstory.  
> Please read the tags and please don't cause undue stress to yourself by reading this if you dislike anything you see in the tags!! The teacher/student roleplay is just Byleth quizzing Shulk on dumb stuff.

Shulk stepped in front of Garreg Mach Monastery, observing its cathedral-like entrance and marketplace stalls on either side. Then, he heard clacking footsteps approaching him from behind. Shulk turned around to take in the appearance of his opponent, and saw Byleth tapping a tapered stick like a teacher's pointer against his open palm as he neared, then tucked it away inside his sleeve and produced a sword instead.

“Well then,” the tall and serene professor said as he swung the blade, and Shulk's eyes widened as its segments seperated, slithering like a chain whip. Byleth concluded, “Let's begin the lesson, shall we?” which made Shulk's mouth hang open, but it quickly clicked closed when a shudder crawled up his spine. He had only barely composed himself as the match began in earnest at that instant.

As they clashed together, Shulk caught himself distracted at various times by his opponent's black leather clothing with light armored elements, especially those slim-fitting boots and gloves. His hair looked soft and his eyes were like a doll's, with long lashes especially along the lower curve of his eyes.

Perhaps that distraction contributed to the blow Shulk took from Byleth's spear, which slammed him back against a table that broke into pieces underneath him. Their battle had moved into a lecture hall, with rows of long tables and benches along each wall, one of which Shulk had been forcibly introduced to. _That's quite a diverse range of weapons,_ Shulk observed dizzily, not quite in the right mind to prioritize the correct things at the moment.

He heard the clack of Byleth's heels slowly approaching where he laid amidst the table rubble, and knew he needed to get his focus back. His swimming vision saw a circle of lights above him, finally focusing enough to make out a wooden chandelier lit with candles. He gripped the Monado, calling upon its power to grant him the most useful art for the situation. Byleth had entered his vision by now, and was readying a terrifying axe, gathering power to swing it over his head and into Shulk, which would surely prove a blow powerful enough to end the match.

But the Monado's swift energy surged through Shulk, and he was on his feet, then off of them again as he leaped in the air as spryly as if his weight were halved. He reached the chandelier in just one jump, grasping the curling shape of one of its arms for grip. The energy blade of the Monado sliced through its hanging chain, and then they were both plummeting, but Shulk had enough momentum to leap out of the way. Byleth had only just finished the slow and powerful swing of his axe, unable to have halted its momentum once he'd started, and the table where Shulk had been laying only a fraction of a second ago was in splinters. He began to look over his shoulder just as the chandelier crashed.

Shulk breathed with relief as victory was declared his, and his adrenaline washed away by degrees. Then, Byleth stood beside him, unscathed, and Shulk took in Byleth's height for the first time. He was _tall._ Shulk's eye line was about at his chin, and he has to raise his eyes to look up at him properly, unconsciously squaring his shoulders to stand up straigher as he did so.

Now that he was looking at Byleth's face outside of battle, he was taken aback by the other man's severe and uncaring expression. Just as Shulk worried that he'd angered the newcomer by defeating him, Byleth crossed one arm over his midsection and bowed, saying, “My thanks for the most enjoyable match.”

When he straightened, he began walking, and Shulk joined step. As they moved, there was a whoosh of blurred, confusing motion as Garreg Mach Monastery reverted to its original, undamaged state around them. “I was worried about the damage we were doing to the place,” Shulk admitted nervously, looking around and unsure how to interact with the well-composed professor.

“It can take it, I've learned, after so many battles here today,” Byleth's cold expression softened to an ever so slightly askew smile, which at least comforted Shulk to know that the professor's face was not completely frozen in such a scowl, after all. He knew, too, of course, that he had not been Byleth's first opponent of the day; not by a longshot. Many of those opponents had naturally wished to see the new location that had sprung up in accompaniment to the latest fighter. Byleth had been rather busy amidst the excitement of his arrival, and Shulk had to remind himself that he was just one more opponent for him.

“It's a beautiful monastery,” Shulk tried changing the subject, his eyes glittering now that he looked over the place again from the outside, where they found themselves after all of the whooshing. “I wish I could examine the stained glass more closely.”

“Perhaps you'll have the chance. If my schedule ever opens up, I'll guide you around.” Byleth's expression was back to looking cold and severe, but his words were kind. Shulk tried his best to acclimate to the fact that he just _looked_ like that.

“That sounds great! But, er, I'm probably keeping you. Next time!” Shulk excused himself, knowing that Byleth had many more matches ahead of him for the day. He started to jog away, but felt Byleth's eyes on him, and peeked over his shoulder. Byleth had his gaze leveled on him, and was holding that instructor's pointer again, with the narrower end in the palm of his other hand. He cast Shulk a nearly imperceptible smile as he idly raised and lowers the pointer into the black leather of his palm. For some reason, it made Shulk's face redden.

  
  


“He kind of reminds me of _you,_ Robin!” Shulk said once he had reunited with Robin in their comfortable and familiar barracks.

“Now, why would that be?” Robin asked with a smile as he sipped from his dark tea at the table.

“He just _oozes_ intelligence,” Shulk's gestured vaguely as if indicating his very aura, which apparently was about the shoulder area. “And he's prim and proper. And he just, like,” Shulk struggled a bit for words, then finally went with, “He looks ready to scold or punish anyone that misbehaves.” He had reddened a bit as he said it, thinking of the pointer, and the leather, and the _whip._

“And that's like me, you think?” Robin grinned as he settled his teacup back in its saucer.

“Well, the first things are, at least. Oh, and you both wear cool dark clothes, with a cloak.”

“I suppose I must concede the resemblence. I've learned as well that we share a love of tea. He invited Marth to tea in the courtyard of Garreg Mach the moment Marth approached him to make his proposition.”

“Already?” Shulk knew exactly what conversation Marth intended to hold with the newcomer. Marth moved quickly when he saw an attractive specimen enter the vicinity.

“I'm sure he's caught on to the same quality of character that you observed.”

“What's that?”

“Big 'step on me' energy.”

  
  


The next time Shulk saw Byleth was the evening of a few days later. Things were always busy in the first days of a newcomer's arrival, and it wasn't until matches had ended for the day that Byleth finally approached Shulk to make good on his promise to show him around the Monastery.

“I heard some very interesting things from Marth,” Byleth admitted, once they had finished talking about flying buttresses. His longer legs gave him a greater stride than Shulk's, so he was positioned a pace ahead, and Shulk could only see the back of his head and the militaristic poise of his hands clasped behind his back.

“Oh, yeah,” Shulk rubbed at the back of his neck. “So... what did you think?”

“I think,” the clack of Byleth's heels on the tiled hall ceased as he came to a stop and pointedly turned, “that you were rather interested in this.” He produced from his sleeve the instructor's pointer, sliding it along the black leather palm of his free hand until it rested in its familiar position, parallel with the ground.

“Well,” Shulk attempted with confidence, but was sure he was failing, he could tell from the heat from his face. “It, er, piqued my curiosity.” _Along with the whip, and the leather, and the boots, and-_

Byleth suddenly lashed out with it, and Shulk flinched, then felt the tip of it under his chin, where the professor used it to tilt his head back. “Perhaps I have been severely underutilizing its potential,” he said, and his narrow lips, usually scowling, lifted into that off-center smile once again.

  
  


Together, they hammered out the details of what else Shulk was “curious” about, and how Byleth could go about satisfying that curiosity. They did this in a teacher's office they'd ducked into, and Shulk couldn't be sure if it was Byleth's or just the nearest one available. Byleth's questions and suggested methods were bluntly to-the-point, as if they were discussing some clinical subject rather than a lay. It all felt very surreal to Shulk to converse about being restrained with a weird chain whip sword in such an impartial and detached way. But, sometimes, when Shulk would make his requests, and Byleth would confirm his ability to fulfill them, he would see the professor lower his long eyelashes halfway and cast his gaze aside, with a tug at the corner of one side of his mouth, and Shulk would know that Byleth was affected by this after all. Perhaps he was even getting a little excited. _If this is Byleth's version of excited, he must be unbeatable at poker,_ he mused.

They even concluded their terms with a handshake, during which Shulk said, “I am in your hands, sir.”

“Sir?” Byleth repeated musingly, rubbing his chin with fingers in a ponderous way. “I could get used to that.”

  
  


“Now, then,” Byleth's gloved finger alighted at the center of Shulk's newly-bared collar bone, having just cast aside his vest and sweater, and traced downward. It raised goosebumps across Shulk's chest, and Byleth concluded his thought; “Let's see how well you've studied.”

“What,” Byleth began, snapping open a textbook with his free hand, and Shulk was at attention, “is the capital city of the country of Ylisse?”

Shulk's head swam. Ylisse was where Robin was from, or, at least where Chrom was from, even if he'd heard that Robin's origins were from a different kingdom, and Robin had fought on Chrom's side, so- He shook his head. He was overthinking. He only had to remember what he had read in the history books Robin had shared with him. “Ylisstol,” he answered confidently.

“Very good,” Byleth's voice was a purr, and Shulk melted to hear it. “You may continue disrobing.” Byleth turned away from him, leafing through the textbook. “For every correct answer, we advance. However, incorrect answers will impede your pleasure. Don't think that wrong answers lead to punishment,” he cast a small, smug grin over his shoulder, “Since I get the feeling that you'd rather view punishment as a reward, wouldn't you?”

Before Shulk could answer, Byleth fired the next question at him. “What is the name of the bar and casino which Captain Falcon frequents?”

“What? Come on!” Shulk groaned, forgetting to be self-conscious about standing there in the buff. He didn't know a lot about Captain Falcon, other than his sweet ride. Why couldn't the question have been something easy, like the specs of the Blue Falcon?

“Are you talking back to your professor?” Byleth scolded, and the pointing stick was at Shulk's throat again as if it were a knife threatening to slit him.

“No, sir,” Shulk sighed. “It's, uh... Mute... Blue... I don't know.”

“Unfortunate,” Byleth left him again, leaving Shulk entirely without stimulation. “The correct answer was 'Dollars.' How about the name of Mr. Cloud Strife's motorcycle?”

 _That_ one was easy. Byleth didn't know that Shulk had ridden that very vehicle! In fact, it had been quite an encounter; one that wouldn't be leaving Shulk's memory soon. “Fenrir,” he answered, remembering how it felt below him, remembering-

“Ah, now we are getting somewhere,” Byleth's voice was filled with promise.

  
  


“Right again,” Byleth praised Shulk's most recent correct answer, and rewarded him with another smack across his buttocks with the pointer. X shapes were beginning to show across the tender skin in red, slowly appearing after each strike.

The hit made Shulk elicit a high-pitched, airy whimper, which Byleth drew out into a groan by tightening his grip on his sword's hilt. The chain whip of his blade was wrapped around Shulk's torso, pinning his arms behind his back, while Byleth's boot against his spine kept him pressed low to the ground.

“You are a most sublime student, Shulk.” Shulk couldn't see it, but Byleth's tongue was curled at the outer corner of his mouth. His deep eyes shone as he took in the sight of the “pupil” literally under his heel, rear end raised in the air and eagerly accepting the strikes from his pointer stick. He had to admit he had never considered it an instrument of punishment before, and here Shulk had not only requested it but was _relishing_ it. He may not ever get the opportunity for it again.

Unless Shulk wished to do this again...

The idea had him grinning with excitement, which further made him grateful that his partner in this act could not see him.

“What is the name of the guardian robot that the Star Fox team finds adrift at the end of Sector X?”

“Oh, shit, uh...” Shulk struggled. “I don't know! But please don't-”

“Such foul language,” Byleth said disapprovingly, relaxing his hold on his chain sword. The red bites in Shulk's skin from the edges of the blade segments showed themselves as it loosened. “Its name is 'Spyborg.' I also would have accepted 'HVC-09.' Now tell me which Pokémon has the Pokédex number of 172.”

“It's...” Shulk reached around for knowledge in his brain through the fog of intensely pleasurable pain. It had to be a Pokémon relevant to Smash, and the number was too high to be one of the original, first generation Pokémon, so that ruled out Pikachu and Jigglypuff and the three that the Pokémon Trainer battled with. But, it was such a close number to 150, it had to be among the major second generation ones...

“Pichu! It's Pichu!” It was just a guess, but a blissful shock of discomfort radiated from his back where Byleth's heel pushed him down so hard, his cheek pressed against the wooden parquet of the office floor, and the blades pinched into his arms and chest as the whip tightened again.

Now looking over his shoulder, what he saw from Byleth amazed him. Gone was his placid expression, and what replaced it was wild and radiating red heat. But, Shulk saw it for only an instant, at which point Byleth turned to direct his attention to Shulk's backside instead, and was raising his pointer. Shulk had time only to appreciate that even Byleth's hair was frazzled-looking before the instrument came down again with an echoing crack.

He yelped a desperate, whining cry, feeling the painful shockwave like fire down his thighs. His cock, thick and rigid below him, dribbled yet more precum. “P-please,” he puled, his face still smushed against the floor. “I can't take any more. I've got to... You've got to...”

“I've got to... what?” Byleth asked cruelly, and he was running his gloved fingers through his hair, pushing back where the long bangs had fallen into his face and contributed to his ragged look. He seemed to know, now, that he was being watched, as he'd attempted to compose his expression, although there was nothing he could do to hide the warm tinge of blood under his flesh and the sweat along his hairline.

“Fhuh... fuhhhhhhcgh,” Shulk lost himself again when Byleth's cruel features gazed down at him, his lips parted as he panted to regain his excited breath.

“Swearing again?” Byleth did his best to sound unenthused, tugging the sword hilt. It squeezed Shulk harder while the heel of his boot kept him in place.

“Yes! Fuck!” Shulk spat, long past the point of holding himself back. “Would you fuck me, please?! _Sir?!”_

Byleth's eyes went wide. For once, he didn't have any reaction of punishment or reward for his treasured “pupil.” He just went for his belt.

  
  


Shulk was sad to feel Byleth's boot leave his back, but accepted it as necessary for what was to come next. The chain wrapped around him shifted as its weilder changed his position. Then, he felt gloved fingers tracing a line down his lower spine to his tailbone, where the fingers spread out and feathered over the stinging wounds from all of the spankings he'd endured. Having warmth and pressure applied to them both hurt and felt good at the same time, which he supposed could be said about a lot of what they'd done that evening.

Then, there was a thumb and the hot head of Byleth's cock at his hole, pushing it open. Byleth, his voice sounding ragged, asked if Shulk was ready, and he groaned an affirmative approximation and nodded his head, which rubbed his cheek against the floor.

Byleth had been just as eager for this step as Shulk had, perhaps, as he wasted no time working his way inside. In their ugency, he'd lubricated himself but neglected to exercise Shulk's entrance, which he felt a little guilty about even if Shulk had insisted he didn't need it in their conversation beforehand. Now that he was inside and Shulk was taut and moaning with pleasure, though, he managed to feel a little less guilty.

The Sword of the Creator had been placed beside him, so his hands were free to grip Shulk's hips and experiment with a few thrusts. The pull of Shulk's hole around him as he went in and out had him gasping; instincts were starting to take over and his bucking thrusts didn't much need his conscious attention any more.

Byleth's longer legs gave him the advantage of height over Shulk's hips, so his thrusts were downward and forward, and he leaned his body over Shulk's battered back. His cape fell over them both, fluttering with the motion of his bucking hips underneath it. As he gazed down at Shulk's back, slick and gleaming with sweat, he saw the beginnings of blossoming bruises where his heel had dug in. _Did I really do that?_ he quesitoned of himself. To maintain his own balance, he gripped Shulk's upper arms, drawing his attention to the young man's restrained forearms crossed behind his back, even if the chain of the sword was slack now that he wasn't holding it. _I did that, too._

And then his gaze went to Shulk's face. The side of his head was still against the floor, eyes shut tight and mouth open and gasping for ragged breaths of air as he took every thrust Byleth fed him. His throat released grunts and whines of a much higher pitch than Byleth expected to hear from him.

Watching Shulk's face in this state sent a rush of blood through Byleth's features anew. _I did... all of this._ Shulk was completely under his mercy, his sensitivity heightened and responsive to everything Byleth did. It was all exactly what he'd asked for, and Byleth had come through and satisfied his every request, even if it was utterly unlike anything he'd ever done before. It had awakened him to some entirely new experiences, that much was for sure; an entirely new avenue of exploration. And, Shulk made it actually seem like his awkward height and resting bitch face were actually desirable for once, instead making fun of them.

His next thought was, _Wow._

Newly invigorated, he reached back to grab the hilt of the Sword of the Creator and tightened its hold on his newest partner. It made Shulk moan, and lifted him off of the floor at last. Byleth had straightened himself, and pulled Shulk upright to meet him, wrapping an arm around his shoulders to hold him in place. Shulk's head lolled, and Byleth steadied him, then had the idea of shoving two of his fingers in Shulk's mouth, since he seemed to like his leather gloves so much. Shulk's lips closed around them at once, and even through the fabric, Byleth could tell he was running his tongue over them, and felt the vibrations of his voice as he moaned. _Yeah, that was a good idea._

“There is something... _really_ special about you,” Byleth grunted into Shulk's ear, sounding a bit breathless himself.

Shulk's mouth opened, perhaps to comment, and Byleth pulled his fingers out. The moment he was free, he had his pointer in his hand again, and was at Shulk's mouth again. He wedged the stick horizontally between Shulk's teeth like a gag.

“Chomp on that bit for a while,” he said, and concentrated on thrusting again. Shulk's mouth was occupied, and his body formed a taut arch thanks to the chain wrapped around him, which Byleth still gripped and pulled back on. Their lower halves, of course, rocked together, all the harder now that Byleth determined it was time to finish up.

  
  


Byleth's knees weakened and he fell back to sit on the floor. He hadn't removed much of his clothes, only shifted them around for access, so now they were bunched around him uncomfortably, but he wasn't in any mind to pay attention to that. His chest heaved with spent exertion, and he could tell from the strands of bangs that had fallen into his vision that his hair was mussed up.

 _That... was..._ he wasn't even sure how to finish the thought. He just stared in disbelief at Shulk before him, who was grunting as he also moved into a sitting position. Golden late-evening light from the window opposite him made the edges of his skin and hair glow, and Byleth entertained that he was watching some beautiful and magnificent creature, or observing a work of art like a nude marble statue. Shulk certainly had the physique for it...

The chain of his sword hung limply around Shulk's midsection, and he shrugged out of it, baring his bruised and battered back without obstruction. _I did that,_ Byleth caught himself affirming again. At the young man's request, he had hurt him, but Shulk himself was rubbing down his arms and looking at the red marks from the blade segments with appreciation. _I did that, and it was... kind of..._ he had looked down at his hands, then hastily balled them into fists, clutching the cloak that was puddled around him, to hide the fact that they were trembling.

“That was fun!” Shulk finished Byleth's own thoughts for him, laughing breathlessly as if they'd only just finished running laps rather than... what they'd just done. Shulk was crawling the short distance closer to Byleth now, and Byleth didn't know what to do as he approached, until Shulk, like a toddler that had determined that it was naptime, said, “Okay, now hold me for a bit,” and collapsed against Byleth's chest.

Byleth had raised his arms to either side in uncertainty, and now that Shulk's weight had settled against him, hesitatingly brought them in to wrap around his shoulders. Shulk hummed and nuzzled deeper against Byleth's chest as Byleth urged his arms to relax, finally embracing him. Shulk's curly yellow hair was just under his nose, and he smelled the spicy herbs from his shampoo. Byleth wasn't sure if he smelled so nice himself; he felt his sweat evaporating under his clothes, chilling him, but Shulk didn't seem to notice or care, and only cuddled closer.

So, Byleth continued to hold him, arms rising and falling with the rhythm of Shulk's slow, sleepy breathing, until the sunlight faded away from the window.

Shulk, in that time, drowsily mused about the interesting specimen that was Byleth as he was held by him, wrapped in all of that black leather. There had been two most fascinating expressions he had seen on Byleth's face, and he couldn't help entertaining the fact that he may be the only person that had seen them. The first was that passionate grin and glimmering eyes that Shulk had seen in the heat of things, when Byleth had towered over him with his boot on his back. The heat of arousal was clearly visible then; arousal caused by the hold he had over Shulk. Shulk had to admit that he was a little bit proud of that.

The second expression had been just now, when he crawled into Byleth's lap to be held. Byleth had looked utterly bewildered, his eyes wide and lips parted, hair swept out of place. Perhaps Shulk's requested activities had been a bit much for him. He would be sure to ask, later, if they ever tried this again, with greater emphasis on Byleth's comfort level.

But, if that first expression had been anything to go by, he had a feeling that Byleth had liked it a bit more than he thought he would.

  
  


“What brings us to the library today, Shulk?” Robin asked, holding the door open for the other as they strode into the library. At once, the familiar aroma of paper and books wrapped around them, a comfort to them both.

“Oh, a little bit of everything,” Shulk smiled, and practically skipped from one section to the other, plucking guidebooks and encyclopedias from the various different worlds of the Smash universe off the shelves as he went.

“Goodness, you aren't kidding,” Robin remarked, seeing Shulk's growing collection.

“Well, you never know what you have to be prepared for!”

**Author's Note:**

> Thank you for reading!! Be safe and happy in all of your endeavors in life, amnd I love you all!! \\(^o^)/


End file.
